Karyotype analysis of three types of soybean of north Shanxi Province

Results are as follows: The chromosomal number of somatic cells of three types of soybean are all 40, and are mainly median and submedian chromosomes. Only one pair of satellites was found in each type, and attached to the largest chromosomes. Xiaoheidou was found to have the karyotype 2n=40=28m+12sm(2SAT); Daheidou was shown to have the karyotype 2n=40=6M+18m+12sm+4st(2SAT); Huangdou had the karyotype 2n=2M+30m+8sm(2SAT). Karyotypes of the three types suggest that soybean had been evolving from unsymmetry to symmetry in karyotype.